Aortic elasticity indices by magnetic resonance predict progression of ascending aorta dilation.

OBJECTIVES

Aortic distensibility and pulse-wave velocity (PWV) are under investigation as parameters by which to evaluate the indication for ascending aorta (AA) replacement. The maximum rate of systolic distension (MRSD) was proposed as a new index of aortic elasticity. The aim of this study was to assess the role of aortic elasticity parameters to predict AA growth rates in patients with AA dilation (AAD).

METHODS

Magnetic resonance imaging (MRI) was performed annually in 65 patients with AA dilation (median follow-up 17 months; 25-75th percentile; range 12-30 months). A significant increase in AA diameter was defined as a ≥2-mm increase.

RESULTS

An increase in AA diameter was found in 42 (68 %) patients (AAD+ group) and absent in 20. Median increase was 0.16 (25-75th percentile; range 0.32-0.7) mm/month. The AAD+ group had a lower MRSD (4.6 ± 2.2 vs 7.4 ± 2.0, p < 0.001) but the same PWV and distensibility. MRSD showed 93.7 % specificity and 75.6 % sensitivity for prediction of increase. Patients with MRSD ≤ 6 had lower progression-free survival times (p < 0.002). After a follow-up of 4.1 years, patients who underwent surgical therapy had lower MRSD and distensibility than others.

CONCLUSIONS

MRSD is an index of aorta elastic properties and is a valuable predictor for progression in AAD.

KEY POINTS

• MRI-derived parameters of aortic wall elasticity predict progression of ascending aorta dilation. • Maximal rate of systolic distension (MRSD) was the best predictor of progression. • Patients with MRSD ≤ 6 had lower progression-free survival (PFS) times. • Patients who underwent surgical therapy had lower MRSD and distensibility. • MRI-derived parameters identify patients with fast progression of Ascending Aorta Dilation.